1. Technical Field
The invention concerns an optical fiber cable or an optical fiber element with several superimposed and joined stacks of optical fiber ribbons and an outer jacket.
2. Description of the Prior Art
Optical fiber ribbons comprise a large number of optical fibers which run flat and parallel to each other in one plane and are enclosed between two adhesive films or are bonded together with a material that can be hardened with UV light. Such optical fiber ribbons are used worldwide and to an increasing degree in the manufacture of optical fiber cables or optical fiber elements. As compared to known hollow or bundled conductors with individual optical fibers placed loosely therein, optical fiber ribbons have a significantly higher packing density and the defined position of the individual optical fibers with respect to each other enables the use of simpler joining techniques such as the mass splicing technique.
To arrange optical fiber ribbons in optical fiber cables or optical fiber elements, it is known to superimpose and join several optical fiber ribbons in a stack and enclose it in a tube-shaped protective jacket. Such an optical fiber element can be used as a central conductor or a number of such optical fiber elements can be twisted around a central strength element. It is also known to arrange stacks of optical fiber ribbons in the grooves of a core running lengthwise in a straight or a helical manner.
All of these known constructions of optical fiber cables or elements have in common that by arranging the square stacks of optical fiber ribbons inside the cable or element, there are large unused cross sections which unnecessarily increase the outside diameter and the weight of the optical fiber cable or element.